In 2009, the National Highway Transportation Safety Administration reported a rate of 1.13 fatal car accidents per 100 million vehicle miles.
In 2009 the National Transportation Safety Board statistic showing an aircraft fatal accident rate of 1.32 per 100,000 hours flown in GA aircraft.
Assuming typical aircraft speed of 150 miles per hour, fatal aircraft accidents occur at a rate of 8.8 per 100 million miles (about 7 or 8 times greater than cars).
As a side note — Nationally, in 1997, there were 21 deaths per 100 million vehicle miles traveled for motorcycles
Sources of information ntsb.gov/aviation http://www.ntsb.gov/aviation/Table10.htm nsc.org http://www.nsc.org/lrs/statinfo/99report.htm National Highway Traffic Safety Administration http://www-nrd.nhtsa.dot.gov/pdf/nrd-30/NCSA/TSFAnn/TSF97.pdf http://www.meretrix.com/~harry/flying/notes/safetyvsdriving.html http://www-nrd.nhtsa.dot.gov/pdf/nrd-30/NCSA/Rpts/2006/810606.pdf http://www.mycentraljersey.com/article/20120703/NJNEWS/307030030/Fatalmotorcycle-crashes-reminder-their-danger